Watch This Drone With Legs Jump For Takeoff Just Like A Bird

A group of researchers have created a working drone that combines the efficiency of fixed-wing aircraft with the ease of takeoff like that of a bird. Imagine your next drone being able to hop over obstacles, walk, and perform jumping takeoffs like the birds in your backyard. The Raven, as the development drone is called, isn't targeted for consumer sales, but is eventually planned for search and rescue missions or package delivery.

When we think of drones, most of our minds immediately go to quad-rotor setups (like DJI's lineup) or pusher-propeller military machines (like the Reaper), but as a team of Swiss researchers discovered, those designs, especially in terms of taking off, aren't very efficient. For one, quadcopters—as well as helicopters and rotary-wing STOL/VTOL aircraft—require a lot of power to get off the ground, while fixed-wing craft may use less energy but need a runway or some external means of launching into the air.

Like almost all discoveries humans have made in history, it turns out that nature has had the answer all along. The Swiss research team at the École Polytechnique Fédérale de Lausanne found that by adding bird-like legs to a fixed-wing puller-propeller drone, their machine, aptly deemed Raven (Robotic Avian-inspired Vehicle for multiple Environments), could spring off into flight like an actual bird. If needs be, the drone can walk to its takeoff site and if there are obstacles in the way, hop over them.

Interestingly, the researchers experimented with other means of takeoff for their design, including gravity-led falls and standing takeoffs (relying on the propeller to lift the craft vertically like a VTOL aircraft would), but found that in this application, the bird-like jumping strategy used the least amount of power. Won Dong Shin, lead engineer for the project said, "It turned out that the jumping takeoff was actually the most energy-efficient strategy. I didn’t expect that result." The team found the overall bird jumps are 9.7 times more efficient than standing takeoffs and 4.9 times more efficient than falling takeoffs.

It must be noted that fixed-winged craft with wheels or a method of launching are more efficient than Raven, but the beauty of the bird-like design is that, like its real-life counterparts, the legs are a means of mobility, obstacle-avoidance, as well as allowing it to land and takeoff from almost any surface. Shin thinks that Raven would be a natural fit for flying in tight, hard-to-access locations, making it ideal for SAR missions or even logistics delivery.

Shin says that work still needs to be done before Raven can be viable for industrial applications. Raven isn't yet programmed to clear more varied types of obstacles, plus the team would like to incorporate vision and haptic sensors for better pilot control. Another plan is to make Raven's wing foldable to allow it to squeeze through even tighter spaces.